Conventional light switches are mechanical single pole single throw switches that operate when two metallic contacts are brought together. To activate the mechanical switch an electrically isolated actuator must be moved by direct human touch; i.e. someone must physically flip the switch. As a result, light switches are amongst the dirtiest places. In medical facilities and nursing homes this is an issue. From a health standpoint, a light switch that does not need to be touched would help minimize the transfer of germs.
Most electronic switches, dimmers and timers require at least three wires to operate. There is the incoming power consisting of a hot and a neutral as well as the connection to the load being controlled, which also consists of a hot wire and a neutral. The neutral is common to both the incoming power and the load being controlled, so the total number of wires is three. But many existing mechanical light switches only have a pair of wires routed to them. It is quite costly and time consuming to rewire a light switch location for three wire operation.
Applicant has developed a proximity-actuated electronic switch requiring only two wires and providing, at minimum, the same load control functionality as a single pole single throw mechanical light switch.